Power take-off



Jan. 15, 1952 w. F. sTREHLow 2,582,466

POWER TAKE-OFF Filed sept. a, 1949 5 Sheeis-Shee l Jan. 15, 1952 w. F. sTREHLow 2,582,466

POWER TAKE-OFF' Filed Sept. 8, 1949 5 Sheeis--Shee 2 Jan. 15, 1952 Filed Sept. 8, 1949 W. F. STREHLOW POWER TAKE-OFF' 5 Shees-Sheet 5 Patented Jan. 15, 1952 POWER TAKE-OFF Walter F. Strehlow, Wauwatosa, Wis.,` assigner to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a, corporation of Delaware Application September 8, 1949, Serial No. 114,559

Thisinvention relates to self -propelledz vehicles generally, and is. more particularly directed to powertaire-off attachments for agricultural tractors. v

With* the; advent of power driven. agricultural implements itV has'long been found. necessary kto equipa farm tractor with` some means, deriving power from the: engine, affordingr an external source of power. This means is commonly referred; to as a` power take-off. and` may be in any of several. forms including abelt pulley drive, a rotaryv shaft f or a hydraulic lift mechanism. Oftena tractor is provided with two ormore such power take-oils and in suchcase itislnot uncommon to combine'two of ther power take-offs into one unit receiving. power from a singley place on thetractor drive- Applicants invention iscon cerned with, theflatter type arrangement andi provides aplurality of external power sources affording. rotary and reciprocating movement, respectively, of devices driventhereby Power take-of devices known heretofore which provide both rotary motion and hydraulic pumping actionV have'- beenV relatively large and not readily adaptable for use on the smaller type tractors where available. space.A for such anattachment is at a. premium. And itis, therefore, the primary object ofA the present invention to provider a unitary structure affording both rotary andhydraulic power which is; small and compact with` afminimum number ofparts.

Another object of this invention is to provide a.. tractor power take-off unit comprising par-.ts constructed and arranged in a novel and improved manner whereby both. a rotary shaft Aand a hydraulic. pump may beselectively. driven from thetractor independently of any forward motion ofthe tractor. n.

, Another object of this invention is to provide a vtractor power taire-off` unit. including a. hy-

7 Claims. ('Cl. 'T4-15.63)

draulic pump and a'rotary shaft. comprisingy -a housing. unit disposed and arranged in a novel and' improved'. manner whereby asingle source of lubricant .serves both as. a reservoir for said., pump andas asonrce of lubricant for said rotary shaft anddriving parts therefor.

The construction and operation oil apparatus embodying the invention will become readily apparent as the, disclosure progressesand particularly points lout additional objects andi advantages of special importance. 1 And accordingly, thepresentinventicn may be considered asoom.- prising. the various constructions,V combinations and/oi-subcomhination of parts as is hereinafter `more .fully set forth. in the. detailed. description 2 andv appended. claims, reference being had to. the accompanying drawings, in which:

Fig. 1. is a; partial plan view of a tractor em.- bodying the present-invention with parts omitted or broken away for sake. of clarity;

Fig. 2`is1ay sideA view of the structure shown in Fig. 1, with the rear driving wheel andbelt pulley broken away;

Eig. 3y is an enlarged view taken along line III-III in Fig. 2;

Fig.. 4 is an enlarged view taken along. line IV-IV in Fig. 3.; K

Fig.. 5 is a view taken along line V-V in Fig. 3;

Fig... 6 is an enlarged view taken along line VI--VI in Fig. 3;

Fig. 7 is` ar view taken. along line VIL-VIIv in Fig..6;

Fig.. 8 is` a view taken along line VIII- VIII in Fig. 6;

Fig. 9 isa view taken along line IX-IX in Fig. 8y showing the. control valve in its lift position;

Fig. 10y is a view similar to Fig. 9 with the control valve for the. pump in its lower position;

Fig. 11 is another view similar to Fig. 9 and showing. the pump control. valve in its hold position.; and y Fig. 12 is a. view similar to Fig. 4 showing a modied form ofA the present invention wherein the. shaft. journaled'in the power take-olf housing has. been extended to provide an additional external source of power.

Referring to Figs. land 2,.it willi be seen that theapparatus chosen to illustrate the present invention comprisesr generally a tractorr having a rear driving unit 2 and a forwardly extending frame 3.. The rear driving unit includes atransverse. nal drive housing 5 having an. enlarged central portion V6 operatively enclosing aconventional differential drive mechanism 'l and having -apair vof oppositely projecting axle shaft housings 8 each enclosing an axle shaft l D having its inner endA operatively connected with. the diiTerentia-l mechanism. The outer or exposed end of each axle shaft terminates in a radially flanged hub portion I I having fixed thereto, as by bolts I2, the. central disk portion 13 of a driving wheel l5. The central portion 6 of the. final drive housing includes an integral forwardly extending portion ItI enclosing a changeV speed gearing I 8 operatively connected with. differential mechanism. `.1 andwith the driven element 30 of a conventional type clutch la enclosed in a clutch housingv l1 detachably bolted or otherwise secured to the rear side. of the; finalv drive housing liV in rearwardly overhanging. relation thereto.

A conventional internal combustion engine is detachably bolted to the rear end of housing |1 and is thereby supported in rearwardly overhanging relation to central portion 6 of final drive housing 5, and the adjacent end of the engine crankshaft 28 entering housing |1 has mounted thereon the driving element 29 of clutch I9. Suitable control means (not shown) are provided for the driving unit within easy reach of an operator seated at station 2| mounted on a rear portion of the forwardly extending frame portion 3. It is believed that the foregoing description of certain portions of the tractor is sufcient to properly explain the construction and operation of parts embodying the present invention.

Looking also at Fig. 3 it will be seen that clutch housing |1 has an opening 22 in one side Wall thereof and a power take-off housing 23 is placed in covering relation thereto and secured in place as by bolts 24 (Fig. 12), with communication therebetween through opening 22 and a similar opening 25 in housing 23. The power take-off housing 23 (see also Fig. 4) has a shaft 26 rotatably mounted in bearings 21 carried by opposite end walls 3| and 32 of housing 23 with the shaft thereby positioned generally parallel to the longitudinal axis of the tractor. A gear 33 is carried by a portion of shaft 26 adjacent end wall 3| and is supported thereon, as by bearing 34, for rotation relative thereto. A portion of this gear extends through opening 25 in the side of the power take-off housing adjacent opening 22 and meshes with a reduction gear 36 rotatably mounted in clutch housing |1 in driven engagement with pinion 31 on engine drive shaft 28. Thus gear 33 is constantly driven with the engine drive shaft.

As best seen in Fig. 4 one end of shaft 26 extends through and beyond the forward facing wall 3| of housing 23 and this extending portion of the shaft has fixed thereto, as by key 4|), a gear 4| comprising one pumping element of a hydraulic gear pump. A stub shaft 42 having a portion fixed in wall 3| is disposed in vertically spaced relation to shaft 26 and rotatably mounts thereon a second gear 43 disposed in constant meshing engagement with gear 4|.

Within the main portion ofthe power takeoff housing there is xed to shaft 26, as by a key 46, a bevel gear 41 disposed in close relation to idler gear 33. Bevel gear 41 has a pair of circumferentially spaced transverse openings (not shown) through an intermediate portion thereof which are alignable with any of several similar pairs of openings 48 in idler gear 33 and a pair of shiftable keys 50 are positioned in the openings through gear 41 for selective axial movement into and out of engagement with a corresponding pair of the openings 48 in idler gear 33. With keys 5|) engaging idler gear 33 the two gears are locked against relative rotation and, consequently, any power applied to idler gear 33 will be transmitted to bevel gear 41 and shaft 26.

For manually effecting an axial shifting of keys 5) there is provided a shift collar 5| slidably mounted on shaft 26 in concentric relation thereto and including as part thereof a shoulder portion 52 engaging and coacting with keys 5i) to provide for movement of these parts as a unit. A circular flange portion 53 of collar 5| engages a shifting fork 55 flxedly supported in depending relation to one end of a generally horizontal arm 56 which is supported at its other end by a vertically disposed rod or the like 51 rotatably mounted in the upper wall 58 of housing 23 and extending therethrough. A compression spring 59 on rod 51 between arm 56 and the under surface of wall 56 provides a biasing means for maintaining an engaging relation between shifter fork and the shift collar portion 53. The portion of rod 51 extending above wall 58 of housing 23 has a hand lever 6| nonrotatably fixed thereto and upon movement of this lever a turning movement of rod 51 is effected to swing arm 56 and thereby move shift fork 55, shift collar 52 and keys 5l! in a direction generally parallel to shaft 26. A position indicating detent mechanism is provided for shift lever 6| (Fig. 6) comprising a compression spring 62 seated in a generally vertical bore 63 in the upper Wall of the main housing 23 and a ball 65 seated thereon for engagement with a complementary recessed portion on the under surface of hand lever 6|. 'I'hus the operator can readily ascertain when he has moved the lever 6| sufcient to shift keys 53 into openings 48 in idler gear 33 by feeling ball 65 move into the recess or grooved portion of the lever.

It will be noted also (see Fig. 3) that the main portion 23 of the power take-off housing has another opening 66 inthe side wall thereof directly opposite opening 25 communicating with the clutch housing. A laterally projecting pulley shaft housing portion 61 is disposed in enclosing relation to this opening and detachably fixed to main housing 23 as by bolts 69. Bearings 68 at opposite ends of housing 61 rotatably support a pulley shaft 1| having a belt pulley 12 detachably fixed at the outer end thereof as by bolts 13 and having a bevel gear 14 fixed on its inner end for meshing engagement with bevel gear 41 on shaft 26. Thus it is seen that pulley 12 and pump gears 4| and 43 are driven simultaneously by the tractor engine upon engagement of shiftable elements 56 with idler gear 33.

And referring now to Figs. 4 and 6 to 11, inclusive, it is seen that the hydraulic pump portion of the apparatus disclosed comprises generally a relatively fiat pump body 16 disposed in covering relation to the forwardly facing end wall 3| of the power take-olf main housing portion 23 in enclosing relation to gears 4| and 43, and a pump control housing 11 serving as an end plate for the pump body and mounting a pump control means on the upper portion thereof. Suitable means, such as bolts 16 (Fig. 3), secure pump body 16 and control housing 11 in detachably fixed relation to main housing 23. Affording communication between the source of oil in clutch housing I1, normally at a level indicated by the numeral 19, and pump body 16 is a series of passages including a tubular part 80 (Fig. 3) extending into clutch housing |1 and joined at one end to a passage 6| in main housing portion 23, a passage 62 disposed at a right Yangle with respect to the end of passage 8| remote from thel clutch housing and an intake chamber or passage 83 (Figs. 6 and 7) placing passage 82 in communication with pump body 15.

Pump body 16 has a relatively large opening therethrough forming a chamber B5 (Figs. '1 and 8) for pump gears 4| and 43 and communicating with intake chamber 83 and a discharge passage means 86. Pump control housing 11 includes the pump discharge passage means 86 which comprises a generally vertical passage 31 extending upward from a point adjacent the meshing teeth of the pump gears to a horizontal passage 88 in anenlarged portion of the pump control housing.

2A lverticalcylindrical chamber 95 .is `formed in L control housing 171'! at a point intersecting 'horie f 'rental passage .|88 intermediate the ends thereof and .this chamber houses a rotary plug valve 06 controlling `thelow of huid through the passage. More lspecically, this .generally .cylindrical valve .Ellil .isA positioned in chamber SI5 'for :rotation :about iitsaxis andhas a transverse bore :'91 `therethrough .i allgnabie with horizontal passage 88 .to 'permit the 'flow .of fluid from the discharge .passage to fthe. outlet passage. :Control valve 9.6 also includes oppositely facing 'vertically 4grooved portions |00 and .|01v '(Eigs. 39 to 11'.) disposed .generally latvrigh-t angles with respect vto transverse bore 101 Aand having their lower end portions =.disposed Ain the .bot- :tom ,portion of the control valve chamber. These loppositely facing grooves .are .selectively .alignablc with :adjacent portions of .horizontal passage `80 to place the discharge passage and the outlet pas;

sage, respectively, .in .communication 'with lthe' lower portion of valve .chamber :95. 'The lower portion of control .chamber 105 has .communica- `tion with .la ,generally vertical return passage i|2 Channel .in :turnV empties at .one end into ipulley-shaft housing 16:1 `and at kthe yother .end into Amai-n housing portion 2.3 .of 4the power take-oil.

- .Referring to Fig.. y8 it is seen that .control housjing IJ also includes a second. .horizontal passage 1I-0.6 affording a pressure relief passage .means for lathe pump and. communicating at opposite end` portions with discharge passage 8l :and return passage .|\.0.2. .Relief passage '|106 :includes ltherein a spring biased lball check valve assembly |103 `controlling .now through the opening fat the high pressure :side .and .respons-ivato attainment .of 'ay predetermined pressure in discharge vpassage 'B1-I toplace samein fdirectcommunication with return .passage `means |02..

. Control val-.ve 9S. .includes a reduced ripper :end

portion `|00 extend-ing through the top :surface .of

control housing .1:1 and having a transversely dis,- posedplate-lilse `part H10 nxerlly .mounted thereon ain slidably engaging relation to the :top .surface of the housing. Plate He has anfarcuate slot ilgilsl (Figs. -1 and l6.) adjacent one edge l.thereof .andi-a ncap screw `I |32 threaded 'into .a .bore il I3 in the vvupper portion of control .housingl l' positioned through this slot. .Plate :I I0 is fessentiallya .letter p'votable about .the :axis of .the 'control valued-n unison therewith and has :an opening |15 through an end Vthereof remote from valve '06 aiording suitable vconnection with one endv of .a hand 4control lever :assembly H6. Slot :and cap screw l| I2 coact to .limit the range of movement of the lcontrol Lvalve from lift position, wherein bore .91 .is positionedv to place .discharge passage 188 communicationwith outlet passage 09 '.Cligsp and 9.) ,1i-toa lowefposition (Fig. 1.159 .placingthe vertical' grooves. 10.8. and |02! in lposition to effect a discharge to return passage IM and a return `of duid from Voutlet passage Hilfto the 'return passage. There isfal-so 'provided a .means for adjust- .ably limiting the movement of control vala/e in .lower position comprising. a :knurlecl adj ust frat-ns.

4somewhere between that shown 4in Fig. 11 .and

`the hold position in Fig. 10.

n The .operators .hand lever assembly 'I |`6 .comeprises generally .a krod 1.20 having the rear end .portion bent to pass through opening |125 in plate |10 (Fig. 18) .and piyotally securedztherein :by suitable means .such :as .pin |12r| .and having the forward. end kportionwpivotally attached to the lower .end of a :crank arm |22 `v(Figs. 1 and 12T) `which is pivotally mounted .on the "tractor, :and .a 4forf- Wardly extending hand .rleyer |23 .having connectionfwith :arm |22 .for effecting rotation of same relative .to the tractor. A spring biasing means :is provided "in Iorder to effect :1a :return 'of the hand .lever to .fa .neutral or hold position l(wherein :the leyeris positioned .as :seen in Figs. l .and .2 .arid uthe cont-rol valve iis .thereby moved to the position shown .in Fig. l1) when released 'from its v:raised or flirt position (sh-'own .as A .in broken lines in Fig. 2=).. This biasing means comprises la compression .spring 1| 25 (Figs. 1 and .25) surrounding `rod and fixed .against `'movement in .onedirection by any :suitable meanssuch :asfwasher andl assembly |26, a 4sleeve like pant |21 'positioned Eat `,the opposite-:end of spring 1F25 and :having a collar providing .a seat for .the spring, .and a bracket |228 mounted -.on the tractor restraining sleeve 1:27 from Torwardsliding .move- Iment along rod '|20.. "Titus when lever .|123 'is moved .upward ato position A, wherein valve fgfis placed .in :its "lirt position with A.discharge to :the .outlet 90,;spring is compressed 'between vwasher :|25 vand sleeve .|:2.| and release :of the lever lwill cause thespring Lto expand to -its full length .and .return l'ever I 23 toits neutral (ff-hold aposiltion 'for valve 95) position B. Downward moyementnf 'lever 123 to posi-tion C' (lower position for :the value.) is not aiected 'hy the .spring and, .conseouently, the leyer will remain at :any selected position between .B and :C until manually 'repo- .sitioned .'It will be further noted Figs 1 and 21l that the pump control apparati-.rs includes :a "two way valve |30 positioned; yon the tractor -to receive iiuid through Ia single hose 292 connectedito the pump outlet and affording selective communicaf ltionwith eithera'front mounted Arain (lnotshcwn) through hose |;3.| or a A,rear mounted ram |32 through .hose |33. This two Way valve 'is also controlled by- `Ahand lever |223 which is connected therewith through a :linkage 'including an farm |35 fixed to lever |23 .and 12a 'link :|35 .connecting the free rend portion of .arm with .a .smaller arm. .|31 .fixed .to lthe valine. Rotation .of leser |123 about its. .longitudinal axis effects va rotary :movement .of .the .flow control part Knot shown) of valve |30 to selectively :afford vvc0mm-unication 'between the pump .and either of the hydraulic A further description of .this 'portion of' the apparatus :is believed.unnecessary vfor a com'- :plete understanding 4.of the present intention.'

'Having in mind the construction and arrangement of parts in the hydraulic system ius-it described, `the details of the operation of 'this .system will now be described. .Looking particularly at Fig. 4 it is seen that when shift elements '50 are moved into engagement with idler gear 33, bevel gear 41, shaft 26 and pump gear 4| are driven in unison by the tractor engine. The rotation of pumping gears 4| and 43 within the confines of the pump body 16 create a suction sufficient to draw oil from clutch housing |1 through passages 8| and 82 into intake chamber 83 where it is caught between the meshing teeth of the gears and discharged under pressure into passage 81. From this discharge passage the oil is directed by control valve 96 either into outlet passage 90, from whence it travels through the two way valve to one of the rams, or down through valve chamber 95 to return passage |02 from where it flows through channel |05 into the pulley shaft housing 61 and the main housing portion 23. And when the oil level in main housing 23 gets above the side wall portion |38 (Fig. 3) the oil flows into clutch housing |1.

In the event the pressure in discharge passage means 86 exceeds a predetermined amount at any time the ball check valve |01 (Fig. 8) is forced off its seat and the pump discharges through relief passage |06 to return passage |02 until the cause for the excessive pressure is eliminated and discharge at operating pressure is resumed.

As shown in Figs. 9, 10 and 11 the operation of hand lever |23 rotates control valve 96 through approximately 90 degrees and with the lever in position A (Fig. 2) the valve will be positioned as shown in Fig. 9 with discharge passage 83 in communication with outlet passage 90. When the lever is moved to position B the valve assumes the position shown in Fig. l0 with the ram outlet passage blocked olf, thereby trapping any fluid' in the rams, and vertical `slot |00 is positioned to afford flow from the discharge passage to' return passage |02. With the lever in position C the control valve is positioned to afford communication between discharge passage 88 and return passage |02 through slot |00 and also to permit the return of fluid from the rams through outlet passage 00 and slot |0| to return passage |02 (Fig. 11).

And in connection with control lever |23 and control valve 06 it will be noted (Fig. 6) that a hold position indicating means has been provided in the form of a ball and detent device |40. More specifically, a bore |4| in the upper portion of control valve housing 11 has seated therein a spring |42 and ball |43 which coact with an opening in plate |0 to indicate to the operator when lever |23 has been moved to a position placing valve 96 in the position shown in Fig. 10.

A modified form of this invention is shown in Fig. 12 wherein shaft 26 has been extended through rear lend wall 32 of the power takeoff housing and the projecting end portion has been splined to receive a' coupling element thereon (not shown) for transmitting rotary power to an implement or the like. Thus it will be seen that with such an arrangement there is provided an integral power take-oir unit affording .three different sources of power selectively driven in unison by the tractor engine. r

And although shown and described as applied to particular forms of power take-off, it should be understood that it is not thereby intended to limit the invention to the exact construction and combinations shown and described as certain features thereof are of more general application and as various modifications within the scope of the appended claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In a power take-off mechanism, a rst housing having a shaft journaled therein with one end of said shaft extending through and be'- yond one wall of said housing, a first gear in said housing fixed to said shaft for rotation therewith'. an idler gear rotatably mounted on said shaft in adjacent relation to said first gear and adapted for meshing engagement with an external drive gear, means for selectively connecting said first and idler gears for rotation in unison, a power take-off shaft rotatably supported by said iirst housing and extending outwardly therefrom, a second gear fixed on an inner end portion of said power take-off shaft for rotation therewith in meshing relation with said first gear, a housing portion disposed in covering relation to said one wall of said first housing and enclosing said one end of said first mentioned shaft, a hydraulic pumping element carried by said housing portion adjacent an interior wall thereof, and a third gear mounted on said one end of said first mentioned shaft for rotation therewith and having a driving engagement with said pumping element.

` 2. In a power take-off mechanism, a first housing having a shaft journaled in opposite end walls thereof with one end of said shaft extending through and beyond one of said end walls, an element in said housing iixed to said shaft for rotation therewith, an idler gear rotatably mounted on said shaft in adjacent relation to said element and adapted for meshing engagement with an external drive gear, means for locking said element and idler gear against relative rotation, a hydraulic pump comprising a housing portion enclosing a pumping element and disposed in covering relation to said one end wall of said first housing in covering relation to said one end of said shaft, a pump gear mounted on said one end portion of said shaft for rotation therewith and having a driving connection with said pumping element, and external power take-off means deriving power from said shaft when said element and said idler gear are locked against relative rotation.

3. In a power take-off mechanism, a first housing having a shaft journaled in opposite end Walls thereof with one end of said shaft extending through and beyond its supporting wall, a first gear in said housing fixed to said shaft for rotation therewith, an idler gear rotatably mounted on said shaft in adjacent relation to said first gear and adapted for meshing engagement with a drive gear external of said first housing, a power take-off shaft rotatably supported by said first housing and extending outwardly therefrom, a second gear mounted on the inner end portion of said power take-01T shaft for rotation therewith in meshing relation with said iirst gear, a hydraulic pump comprising a housing portion enclosing a pumping element and disposed in covering relation to said one end wall of said first housing in enclosing relation to said one end of said shaft, a pump gear mounted on said one end portion of said shaft for rotation therewith and having a driving connection with said pumping element, land shiftable means carried by said rst gear and selectively positionable through an alignable opening in said adjacent idler gear whereby said pump gear and said power take-off shaft may be simultaneously driven.

4. In a power take-off mechanism, a first housing having a shaft journaled therein with one end of said shaft extending through and beyond one wall of said housing, an element in said housing fixed to said shaft for rotation therewith, an idler gear rotatably mounted on said shaft in adjacent relation to said element and adapted for meshing engagement with an external drive gear, means for selectively connecting said element and idler gear for rotation in unison, a hydraulic pump comprising a housing portion enclosing a pumping element and disposed in covering relation to said one end wall of said first housing in covering relation to said one end of said shaft, pump drive means mounted on said one end portion of said shaft for rotation therewith and being operatively Vassociated with said pumping element, and external power take-oii-means deriving power from said shaft when said element and idler gear are connected for rotation in unison.

5. In apower take-off mechanism, a rst housing having a shaft journaled in opposite end walls thereof with the ends of said shaft extending through said walls and projecting outwardly from said housing, an element in said housing fixed to said shaft for rotation therewith, an idler gear rotatably mounted on said shaft in adjacent relation to said element and adapted for meshing engagement with an external drive gear, means for selectively locking said element and idler gear against relative rotation, a hydraulic pump comprising a housing portion enclosing a pumping element and disposed in covering relation to one of said end walls of said first housing in enclosing relation to one end of Y,

said shaft, a pump drive means mounted on said' one end portion of said shaft within said pump housing and operatively associated with said pumping element, and additional means on the other end portion of said shaft comprising an external power take-off driving power from said shaft.

6. In a power take-off mechanism, a first housing having a shaft journaled in opposite end walls thereof with the ends of said shaft extending through said walls and projecting outwardly from said housing, a first gear in said housing fixed to said shaft for rotation therewith, an idler gear rotatably mounted on said shaft in adjacent relation to said first gear and adapted for meshing engagement with an external drive gear, means for selectively connecting said first and idler gears for rotation in unison, a power takeoff shaft rotatably supported within said first housing and extending outwardly therefrom, a

second gear flxedly mounted on the inner end' portionof said power take-off shaft in meshing relation with said first gear, a hydraulic pump comprising a housing portion enclosing a pumping element and disposed in covering relation to one end wall of said first housing in enclosing relation to one end of said shaft, a pump drive means mounted on said one end portion of said shaft for rotation therewithA and operatively associated with said pumping element, and addtional means on the other end of said shaft comprising an additional external power take-off deriving power from said shaft.

'7. In a power take-off mechanism, a first housing having a shaft journaled in opposite end walls thereof with one end of said shaft extending through and beyond one wall of said housing, said first housing also having an opening in one side wall thereof and being adapted for detachable connection to a lubricant confining housing having a drive gear mounted therein and having an opening communicating directly with said opening in the side wall of said first housing, an element in said rst housing fixed to said shaft for rotation therewith, an idler gear rotatably mounted on said shaft in adjacent relation to said element and adapted for meshing engagement with said drive gear, means for selectively connecting said element and idler gear for rotation in unison, a hydraulic pump comprising a housing portion enclosing a pumping element and disposed in covering relation to said one end wall of said first housing and said one end of said shaft, a pump drive means mounted on said one end portion of said shaft for rotation therewith and being operatively associated with said pumping element, external power take-oif means deriving power from said shaft when said first mentioned element and idler gear areconnected for rotation in unison, means defining a first passage extending from said first housing and adapted for communication with the interior of said lubricant confining housing, and additional passage means in said first and pump housings affording communication therebetween and placing said first passage in communication with said pumping element.

WALTER F. STREHLOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,436,442 Hodge Nov. 21, 1922 2,448,822 Pinardi et al Sept. 7, 1948 2,475,242 Iavelli July 5, 1949 2,495,988 Sheppard Jan. 31, 1950 

